FORT LAUDERDALE, FLA. – Orthopedic crises are common in patients with sickle cell disease, ranging from osteonecrosis to bone infarction, and physicians who manage these patients should know how to recognize these crises and not hesitate to consult an orthopedic surgeon early on, according to one expert at the annual meeting of the Foundation for Sickle Cell Disease Research.
“Sickle cell is a common entity in orthopedic surgery, so you shouldn’t hesitate in the hospital or outpatient settings to call for an orthopedic surgeon when you’re dealing with acute pain crises, medullary infarcts, and osteonecrosis,” said, an orthopedic surgeon with Orthopaedic Associates in Southern Florida.
Dr. Bridges noted that the femoral head is the most common location for osteonecrosis, one of the four major orthopedic manifestations of sickle cell disease that he reviewed. The others are septic arthritis, osteomyelitis, and bone infarction.
“Bone infarction is more common than osteomyelitis, and gadolinium-enhanced MRI can help to differentiate the two,” he said.
Osteonecrosis occurs when ischemic cells die, weakening the subchondral bone. Besides the femoral head, osteonecrosis commonly affects the humeral head of the shoulder and the femoral condyles of the knee. Dr. Bridges reviewed the five stages of the Ficat and Arlet classification of osteonecrosis:
- 0 – no pain, normal x-rays.
- I – pain, normal x-rays but abnormal MRI.
- II – pain, abnormal x-ray (sclerosis without collapse).
- III – pain (subchondral collapse without joint degeneration).
- IV – pain (arthritic changes with subchondral collapse).
For osteonecrosis of the shoulder, Dr. Bridges said four surgical options exist: core decompression for stages I and II; humeral head resurfacing for stages II and III; and hemiarthroplasty or total shoulder replacement for stages III and IV.
“No medical therapies are known to slow the progression,” he said.
Total joint replacement can be inevitable in these patients when total collapse of the joint occurs, but Dr. Bridges added a word of caution. “Overall when it comes down to replacing joints, there are more complications in patients that have [sickle cell disease],” he said. “Normally the complication rate is about 1%; that typically goes up to about 10% in SCD patients, but when you have a patient with end-stage disease – shoulder collapse or hip collapse – you have to do something.”
Septic arthritis is an infection within the joint space, most commonly the hip, and it affects 5% of children and 0.3% of adults with sickle cell disease ().
“This is very similar to a vaso-occlusive crisis,” Dr. Bridges said.
MRI with gadolinium can help guide treatment, and blood cultures and joint aspiration can identify the infectious microbe. Staphylococcus aureus is the most common, Dr. Bridges said. Treatment consists of IV antibiotics, irrigation, and debridement.
Osteomyelitis is an infection within the bone with symptoms similar to those of septic arthritis, although osteomyelitis patients are typically sicker, he said. MRI with gadolinium is indicated in patients who don’t respond to IV fluid, oxygenation, and nonsteroidal anti-inflammatory drugs. “Try to treat them like they have vaso-occlusive crisis,” he said. Blood cultures usually suffice in these patients; bone aspiration is rarely needed, Dr. Bridges said.
The most common organisms are Staphylococcus aureus and Salmonella, and sickle cell disease patients can have infections in more than one location, Dr. Bridges noted.
“If IV antibiotics don’t work, then these patients need surgical debridement,” he added.
Adults are prone to a higher rate of complications than are children, including joint stiffness, osteonecrosis, pathologic fracture, and chronic osteomyelitis.
Ischemic marrow from vaso-occlusion can result in bone infarction. With its severe pain, swelling, erythema, and loss of motion, bone infarction can appear similar to osteomyelitis and septic arthritis, although a high-grade fever is uncommon in bone infarction. Unlike osteomyelitis, gadolinium on MRI does not enhance in bone infarction.
Treatment “consists of supportive management with pain medications, hydration, and antibiotics until osteomyelitis is ruled out,” Dr. Bridges said.
When a patient with one of these orthopedic conditions needs surgery, there are three considerations: preoperative transfusions to achieve hemoglobin level of 10 mg/dL for major procedures; no transfusions for arthroscopy and small closed reductions; and postoperative oxygenation and hydration to prevent a vaso-occlusive event and acute chest syndrome, he said.
Dr. Bridges reported having no conflicts of interest.